Integumentray System

Question 1

Functions of the integumentary system

Answer 1

• protection (Form barrier, immune responce, prevent water loss)
• thermoregulation(Sweat cools: Fat insulates)
• Sensation ( touch, pressure, pain, temperature)
• Storage ( lipids and adipocytes)
• Vitamin D Synthesis (Uv light stimulates Sun thesis)
• Excecreation ( water, urea, salts)

Question 2

Three layers of the integument

Answer 2

1. Epidermis (skin)
2. dermis (skin)
3. hypodermis (fat layer)

Question 3

What tissue does the epidermidis consist of

Answer 3

Stratified squamous epithelial

Question 4

3 main cell types of the integument

Answer 4

Keratinocytes: Produce protein keratin,Most superficial cells are dead

Melanocytes: Produce pigment melanin,UV radiation stimulates melanin production, tan
Products against UV radiation

Dendritic Cells: Immune function (macrophages that patrol the skin), Protect against pathogens/cancer

Question 5

LAYERS OF THE EPIDERMIS

Answer 5

COME LETS GET SUNBURNED

Stratum corneum, stratum lucidium, stratum granulosum, stratum spinosum

Question 6

Stratum Corneum

Answer 6

“Horny” layer

• Up to 30 layers of dead keratinocytes
• Cells filled with protein keratin
• Protective (cells continually shed)

Question 7

Stratum Lucidum

Answer 7

Clear layer
- Few layers of thin, flat
- Found only in thick skin (plantar, Palmer Regions)

Question 8

which layer of the epidermis is only found in thick skin?

Answer 8

Lucidum Eg. Plantar, soles of feet

Question 9

Stratum Granulosum

Answer 9

• Keratinization begins here
• Keratin fibres bound tightly together by keratohyallin granules
• Gylcolipid granules secreted

Question 10

Stratum Spinosum

Answer 10

“Spiny” layer

• 8-10 layers tightly joined-living keratinocytes
• Intracellular junctions = desmosomes (form tight barrier)
• Dendritic cells here (immune defence)

Question 11

Stratum Basale

Answer 11

Bottom layer
- Single layer of living keratinocytes and melanocytes
- vitamin

Question 12

Facts about the Dermis

Answer 12

• 2nd layer of skin
• Blood vessels/nerves here
• Thick layer off CT
• Various sensory detectors

Question 13

What are the layers of the dermis?

Answer 13

Papillary (top 20%)
- Tissue= loose areolar CT
- Folds (papillae) form ebidermal ridges
- Tactile corpuscle - sensory receptors detect light touch

reticular (bottom 80%)
- Tissue = dense irregular CT
- Thick network of collagen/elastic fibres
- Lamellated corpuscles - sensory receptors detect pressure and vibration

Question 14

Hypodermis

Answer 14

Below the skin

Not a layer of the skin (subcutaneous) of the integument
- Tissue=adipose+areolar
FUNCTIONS: Insulation/lipid storage ,Flexible

Question 15

Sebaceous Glands

Answer 15

• Produce sebum (oily secretion)
• Soften/lubricants hair and skin
• Associated with hair follicles
• Most active during puberty/fetal development
• Functional classification-Holocrine

Question 16

Sweat Glands (sudoriferous)

Answer 16

• Structural classification=simple tuqabular
• Functional classifications=merocrine

Question 17

2 types of sweat glands

Answer 17

Eccrine:
- Abundant over body surface, especially in palmer/plantar areas
- cools body

Apporcine:
- Associated with hair follicles in axillary /anogenital areas
- Secretion is viscous/yellowish (contain fat/proteins)

Modified apporcine sweat glands:
Cerminal gland — Secrete ear wax/earumen
Mammary gland — Secretes milk